BMRN vs IBB: Correlation
BioMarin Pharmaceutical Inc. (BMRN) and iShares Biotechnology ETF (IBB) show a moderate relationship: their 3-year correlation of weekly returns is 0.44.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are BMRN and IBB?
Across a 3-year window, the weekly returns of BMRN and IBB correlate at 0.44, moderate. The relationship has been stable: the 1-year correlation (0.44) sits close to the 3-year figure. Stretching to 5 years gives 0.50, with an annualized covariance of 257.6 %².
IBB is one of the assets that tracks BMRN most closely: it ranks #1 out of the 12 assets we track against BMRN. The last year tells two different stories: IBB led by 44.1 percentage points, +11.3% for BMRN against +55.4% for IBB.
How is this computed?
Pearson correlation on weekly returns: ρ(A,B) = cov(rA, rB) / (σA · σB), over windows of 52, 156 and 260 weeks. Covariance is annualized (×52) and expressed in %². Full definitions on the methodology page.
BMRN vs IBB: side by side
| BMRN (BioMarin Pharmaceutical Inc.) | IBB (iShares Biotechnology ETF) | |
|---|---|---|
| 1-year return | +11.3% | +55.4% |
| 5-year return | -21.6% | +26.6% |
| Volatility (ann.) | 28.1% | 20.7% |
| Beta vs S&P 500 | 0.46 | 0.81 |
| Max drawdown (3Y) | -49.8% | -24.9% |
| Market cap | $12.6B | – |
| P/E (trailing) | 176.5 | – |
| Dividend yield | 0.00% | 0.22% |
| Expense ratio | – | 0.44% |
| Assets under management | – | $9.2B |
| Sector / category | US Listed | ETF · Thematic |
IBB, iShares's Health fund, carries $9.2B under management, 235 holdings, a 0.44% expense ratio, a 0.22% trailing dividend yield.
Year-by-year returns
| Year | BMRN | IBB |
|---|---|---|
| 2022 | +17.1% | -13.7% |
| 2023 | -6.8% | +3.8% |
| 2024 | -31.8% | -2.4% |
| 2025 | -9.6% | +28.0% |
| 2026 | +9.9% | +27.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
A structural note: 0.86% of IBB is BMRN itself, so the fund partly moves with the stock by construction.
Are BMRN and IBB good diversifiers for each other?
A fair diversifier. At 0.44, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
FAQ
What is the correlation between BMRN and IBB?
As of 2026-08-27, the correlation of weekly returns between BMRN and IBB is 0.44 over 3 years, 0.44 over 1 year and 0.50 over 5 years.
Is IBB a good diversifier for BMRN?
A fair diversifier. At 0.44, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
What does a correlation of 0.44 mean?
On the −1 to +1 scale, 0.44 describes how much the two returns move together: +1 is lockstep, 0 is independence, negative values mean opposite directions. It says nothing about which performed better.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/bmrn-vs-ibb.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/bmrn-vs-ibb/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: BMRN correlations · IBB correlations
